//==============================================================================
//
//  This file is part of GPSTk, the GPS Toolkit.
//
//  The GPSTk is free software; you can redistribute it and/or modify
//  it under the terms of the GNU Lesser General Public License as published
//  by the Free Software Foundation; either version 3.0 of the License, or
//  any later version.
//
//  The GPSTk is distributed in the hope that it will be useful,
//  but WITHOUT ANY WARRANTY; without even the implied warranty of
//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//  GNU Lesser General Public License for more details.
//
//  You should have received a copy of the GNU Lesser General Public
//  License along with GPSTk; if not, write to the Free Software Foundation,
//  Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110, USA
//  
//  This software was developed by Applied Research Laboratories at the
//  University of Texas at Austin.
//  Copyright 2004-2020, The Board of Regents of The University of Texas System
//
//==============================================================================

//==============================================================================
//
//  This software was developed by Applied Research Laboratories at the
//  University of Texas at Austin, under contract to an agency or agencies
//  within the U.S. Department of Defense. The U.S. Government retains all
//  rights to use, duplicate, distribute, disclose, or release this software.
//
//  Pursuant to DoD Directive 523024 
//
//  DISTRIBUTION STATEMENT A: This software has been approved for public 
//                            release, distribution is unlimited.
//
//==============================================================================

/**
 * @file RinexObsData.hpp
 * Encapsulate RINEX observation file data, including I/O
 */

#ifndef RINEXOBSDATA_HPP
#define RINEXOBSDATA_HPP

#include <vector>
#include <list>
#include <map>

#include "CommonTime.hpp"
#include "FFStream.hpp"
#include "RinexObsBase.hpp"
#include "RinexObsHeader.hpp"
#include "RinexDatum.hpp"

namespace gpstk
{
      /// @ingroup FileHandling
      //@{

      /**
       * This class models a RINEX Observation Data Record.
       *
       * @sa gpstk::RinexObsStream and gpstk::RinexObsHeader.
       * @sa rinex_obs_test.cpp and rinex_obs_read_write.cpp for examples.
       */
   class RinexObsData : public RinexObsBase
   {
   public:

         /// map from RinexObsType to RinexDatum.
      typedef std::map<RinexObsType, gpstk::RinexDatum> RinexObsTypeMap;
         /// map from SatID to RinexObsTypeMap.
      typedef std::map<gpstk::SatID, RinexObsTypeMap> RinexSatMap;

      gpstk::CommonTime time;    ///< the time corresponding to the observations
         /** Epoch flag has the following values
          * 0 ok
          * 1 power failure since previous epoch
          * 2 start moving antenna
          * 3 new site occupation (end moving antenna)
          *   at least MARKER NAME header record follows
          * 4 header records follow
          * 5 external event
          * 6 cycle slip record - same format as observation, but slips not data,
          *   and LLI and SSI are blank
          */
      short epochFlag;
         /** number of satellites in this observation, except when epochFlag = 2-5,
          * then the number of auxiliary header records to follow.
          */
      short numSvs;
      double clockOffset;      ///< optional clock offset
      RinexSatMap obs;         ///< the map of observations
      RinexObsHeader auxHeader;///< auxiliary header records (epochFlag 2-5)

         /// Constructor.
      RinexObsData() : time(gpstk::CommonTime::BEGINNING_OF_TIME){}

         /// Destructor
      virtual ~RinexObsData() {}

         // The next four lines is our common interface
         /// RinexObsData is a "data", so this function always returns true.
      virtual bool isData() const {return true;}

         /**
          * A Debug output function.
          * Dumps the time of observations and the IDs of the Sats
          * in the map.
          */
      virtual void dump(std::ostream& s) const;

   protected:
         /**
          * Writes a correctly formatted record from this data to stream \a s.
          * When printing comment records, you'll need to format them correctly
          * yourself.  This means making sure that "COMMENT" is at the end
          * of the line and that they're the correct length (<= 80 chrs).
          * Also make sure to correctly set the epochFlag to the correct
          * number for the type of header data you want to write.
          * @throw std::exception
          * @throw FFStreamError
          * @throw StringUtils::StringException
          */
      virtual void reallyPutRecord(FFStream& s) const;

         /**
          * This functions obtains a RINEX Observation record from the given
          * FFStream.
          * If there is an error in reading from the stream, it is reset
          * to its original position and its fail-bit is set.
          * Because of the Rinex Obs format, a RinexObsData record returned
          * might not have data in it.  Check the RinexSatMap for empty()
          * before using any data in it.
          * @throw std::exception
          * @throw StringException when a StringUtils function fails
          * @throw FFStreamError when exceptions(failbit) is set and
          *  a read or formatting error occurs.  This also resets the
          *  stream to its pre-read position.
          */
      virtual void reallyGetRecord(FFStream& s);

   private:
         /// Time corresponding to previous set of oberservations
         /// Used in cases where epoch time of a epoch flag==0
      static gpstk::CommonTime previousTime;

         /// Writes the CommonTime object into RINEX format. If it's a bad time,
         /// it will return blanks.
      std::string writeTime(const CommonTime& dt) const;

         /**
          * This function constructs a CommonTime object from the
          * given parameters.
          * @param line the encoded time string found in the RINEX record.
          * @param hdr the RINEX Observation Header object for the
          *   current RINEX file.
          * @throw FFStreamError
          */
      CommonTime parseTime(const std::string& line, const RinexObsHeader& hdr)
         const;
   }; // class RinexObsData

      //@}

} // namespace

#endif
